[DOCS] Add leading slashes to EQL API examples

docs/reference/eql/eql-search-api.asciidoc

@@ -33,7 +33,7 @@ PUT /my_index/_bulk?refresh
 
 [source,console]
 ----
-GET my_index/_eql/search
+GET /my_index/_eql/search
 {
   "query": """
     process where process.name = "regsvr32.exe"
@@ -308,7 +308,7 @@ The following EQL search request searches for events with an `event.category` of
 
 [source,console]
 ----
-GET my_index/_eql/search
+GET /my_index/_eql/search
 {
   "query": """
     file where (file.name == "cmd.exe" and agent.id != "my_user")
@@ -418,7 +418,7 @@ These events must also share the same `agent.id` value.
 
 [source,console]
 ----
-GET my_index/_eql/search
+GET /my_index/_eql/search
 {
   "query": """
     sequence by agent.id